In general, an operator responsible for monitoring and control systems at electric power substations and similar monitors the state of an electric power system or circumstances of operation of equipment managed by a system, and upon affirming event information indicating a change in the state of the equipment for monitoring, surveys the entire system being managed, and must quickly and accurately ascertain the causal factors giving rise to the change in state. Hence various running support technologies to support monitoring tasks of an operator have been introduced in the field of monitoring and control systems.
For example, in the plant monitoring control device of Patent Document 2, past alarm data in monitoring control of plant devices and trend data corresponding thereto are displayed having some kind of relationship. In this monitoring control device, when a change occurs in each data, two types of system data supplied from the system are linked and displayed on the same screen, so that the operator can obtain useful supplementary information for ascertaining causal factors of the change. Combinations of data displayed on the same screen may be chosen freely as appropriate; for example, event list data may be combined with a trend graph for the same date.
However, even if different types of system data are displayed on the same screen, depending upon the operator it is possible that a causal factor of a state change may not be perceived, and the effect of the above technique is greatly affected by the degree of expertise of the operator. That is, combining and displaying a plurality of system data items can provide auxiliary or supplementary information to an operator, but ultimately the operator himself must judge correctly.
Upon affirming event information, an operator creates a memo drawing on what was noticed relating to changes in the various states of the equipment for monitoring, and stores the memo separately as memo information on a paper medium, in an electronic medium, or similar. And, through affirmation tasks performed continuously for various system screens (trend graph screens, event list screens, gas compartment screens, and similar), by comparing event information displayed on screens with the memo information, event factors can be accurately and promptly ascertained. That is, memo information created by an operator in monitoring tasks plays an extremely important role.
As running support technology which effectively utilizes memo information created by an operator, for example the trend graph display device described in Patent Document 1 is known. This technology has the characteristic that an operator creates and stores memo information in a system in advance, and when trend data related to a plant facility is displayed, the stored memo information is displayed together.
In the above technology, memo information appended to trend data and stored is displayed, and by this means the memo information can be utilized effectively as running support information, and rereading of important trend data can be performed reliably. Further, it is possible to file only important data with memo information appended, so that there are the advantages of economy even when storing trend data and of the ability to achieve satisfactory manipulability.
Patent Document 1: Japanese Patent Application Laid-open No. 7-234133
Patent Document 2: Japanese Patent Application Laid-open No. 11-184519
However, monitoring and control systems of the prior art have the following problems. As explained above, the device described in Patent Document 1 employs technology in which, by appending memo information, the reliability of rereading important data and economy when storing data are enhanced. That is, memo information can contribute to improve the degree of utilization of system data (here, trend data), but it cannot be said that sufficient consideration has been paid to handling of memo information itself.
That is, by means of the technology described in Patent Document 1, even when memo information is imparted to system data and displayed, when subsequently the memo information is viewed, it may be difficult to read out the causal factors of an event. This difficulty of reading out tends to intensify with the passage of time, and there is the possibility that the role played by memo information may decline. In addition, the increasing complexity of plant facilities is accompanied by an increase in the quantity of data which is an object for monitoring. Hence there is the concern that memo data may be buried within an enormous amount of data, and so there has been the possibility that memo information, created with considerable effort, may be overlooked.
Further, in technology of the prior art the display destination for memo information is limited to a CRT screen or similar within the system, and information sources when creating memo information have also been limited to trend data. Hence when a memo is created at an alarm screen, the memo information cannot be displayed on a trend screen, and the range over which the effect of the memo information extends has been restricted.
For this reason, an operator must remember at which screen he created a memo, and the burden of tasks imposed on the operator has been considerable, so that technologies supporting monitoring tasks which enhance flexibility have been awaited. In particular, in recent years with increasing electric power demand, stabilization of plant running has become an issue of utmost importance, and the accurate ascertainment of factors giving rise to state changes has become a societal imperative. Hence a monitoring and control system which makes full use of memo information created by an operator and can contribute to enhancement of monitoring performance has been awaited.
This invention is proposed in the light of such circumstances, and has as an object the provision of a highly reliable and highly flexible monitoring and control system which, by displaying memo information created by an operator on an arbitrary system screen, can enhance freedom of memo display and fully exhibit the effectiveness of memo information, and which contributes to accurate ascertainment of the causal factors of state changes and to enhancement of monitoring performance.